Calibration of various analytical methods with heavy‐ion ERDA

Abstract

Heavy-ion ERDA (elastic recoil detection analysis) can be used to characterize thin solid layers. Absolute concentrations of the chemical elements can be detected as well as the layers' thickness and depth profiles. For the measurement, the sample is irradiated with a heavy-ion beam. Atoms of the sample are recoiled and detected with an energy and mass dispersive spectrometer. Since the ERDA principle is based on the classical Rutherford scattering theory, the expected yields for the given conditions can be calculated exactly. Therefore, ERDA is a standard-free method. Absolute concentrations can be determined for all detected chemical elements simultaneously. By comparison with ERDA measurements an FT-IR (Fourier transform-infrared) spectrometer, routinely used to determine the stoichiometry of ZnO layers, was calibrated. Artefacts in SIMS (secondary ion mass spectrometry) data for the characterization of chalcopyrite based solar cell absorbers are ruled out.

TiO2-Protected Photoelectrochemical Tandem Cu(In,Ga)Se2 Thin Film Membrane for Light-Induced Water Splitting and Hydrogen Evolution

“…For resistivity, Hall, and spectroscopic analyses, thin films were prepared on bare 22 × 22 mm float glass substrates. The stoichiometrical composition of these films was qualitatively and quantitatively determined by elastic recoil detection analysis (ERDA; Helmholtz-Zentrum Berlin fu ¨r Materialien und Energie (HZB), 350 MeV accelerated gold ions, angle of incidence 15°; for more information please see ref 26). For these experiments, hydrofluoric acid etched silicon wafers (100 orientation, 4 vol % HF, immediately before film deposition) were used as the substrate.…”